| 摘要 |
PROBLEM TO BE SOLVED: To provide a high acoustic pressure even in a low voltage by constituting a circuit so as to apply the output of a rectangular wave oscillating means on one end of the sounding body and the output of an inverting means on the other end. SOLUTION: In an oscillating circuit 2 comprising an inverter IC as a rectangular wave oscillating means, a rectangular wave is generated in the turning off state of a switch 1, its output is applied on the terminal 3-1 of a sounding body 3, the phase is inverted by an inverter circuit 4 composed of an inverter IC as an inverting means and is applied on the terminal 3-2 of the sounding body 3. In this case, the phases of the respective terminals of the sounding body 3 are reverse phases to each other and the state HIGH and LOW is repeated, the applied voltage becomes a voltage being added by the output voltage of the oscillating circut 4 and the output voltage of the inverter circuit 4 and almost twice of a power source voltage generally in the case of a high impedance load such as a piezoelectric buzzer. Consequently, since a twice voltage of the output of the oscillating circuit 2 is applicable on the sounding body 3, high acoustic pressure is obtained. |
